XML Mapping: Collections with Wrapper element

[jtuchel]

Hi there,

seems I can't figure this out myself...

I have an object model like this
object
+ list (OrderedCollection)
+ listItem

And I want to transport this in an XML stream that looks like this

<object>
<list>
<item no="1"></item>
<item no="2"></item>
</list>
</object>

It seems it's not possible to write xml with the <list></list> tags (in the docs this is called a wrapper tag). My mapping Spec says:

<ClassElementMapping ...>
<AttributeMapping ClassAttribute="list">
<SubElement>item</SubElement>
</AttributeMapping>
...</ClassElementMapping>

I've tried several clever and not so clever things, but it never writes out the wrapper tag.

Do I need a DTD for this purpose? Is there something I've not yet found?

Regards

Joachim

[Diane Engles]

Hello Joachim,
I've been working on updating the JrcOrderExample for Version 8 so that is easier to see how to create Xml output with the wrapper tag. You need to introduce class element mappings and a separate class for the list items. Below is a mapping spec:

Code: Select all

<XmlMappingSpec Name="abtwsdl.map" NameSpaceURI="Vast">

  <ClassElementMapping ElementTagName="Order" ClassName="JrcOrder">
    <AttributeMapping ClassAttribute="number" >
        <Attribute>number</Attribute>
       </AttributeMapping>

    <AttributeMapping ClassAttribute="status">
      <Attribute>status</Attribute>
    </AttributeMapping>
   

    <AttributeMapping ClassAttribute="customer">
      <SubElement>Customer</SubElement>
    </AttributeMapping>

     <AttributeMapping ClassAttribute="lineItems">
      <SubElement>LineItems</SubElement>
    </AttributeMapping>
  </ClassElementMapping>

  <ClassElementMapping ElementTagName="Customer" ClassName="JrcCustomer">
    <AttributeMapping ClassAttribute="customerID">
      <SubElement>CustomerID</SubElement>
    </AttributeMapping>
    <AttributeMapping ClassAttribute="contact">
      <Attribute>Contact</Attribute>
    </AttributeMapping>
    <AttributeMapping ClassAttribute="address">
      <SubElement>Address</SubElement>
     </AttributeMapping>
   <AttributeMapping ClassAttribute="phone">
         <Attribute>Phone</Attribute>   
    </AttributeMapping>
  </ClassElementMapping>

<ClassElementMapping ElementTagName="CustomerID" ClassName="JrcCustomerID">
    <AttributeMapping ClassAttribute="number">
      <Attribute>number</Attribute>
    </AttributeMapping>
    <AttributeMapping ClassAttribute="name">
      <Attribute>namet</Attribute>
    </AttributeMapping>
  </ClassElementMapping>

<ClassElementMapping ElementTagName="Address" ClassName="JrcAddress">
    <AttributeMapping ClassAttribute="street">
      <Attribute>Street</Attribute>
    </AttributeMapping>
    <AttributeMapping ClassAttribute="city">
      <Attribute>City</Attribute>
    </AttributeMapping>
    <AttributeMapping ClassAttribute="state">
     <Attribute>State</Attribute>
    </AttributeMapping>
<AttributeMapping ClassAttribute="postalCode">
     <Attribute>PostalCode</Attribute>
    </AttributeMapping>
<AttributeMapping ClassAttribute="country">
     <Attribute>Country</Attribute>
    </AttributeMapping>
  </ClassElementMapping>

<ClassElementMapping ElementTagName="LineItem" ClassName="JrcLineItem">
     <AttributeMapping ClassAttribute="quantity" StringConversionMethod="asNumber">
       <Attribute>Quantity</Attribute>
     </AttributeMapping>
     <AttributeMapping ClassAttribute="item">
      <SubElement>Item</SubElement>
    </AttributeMapping>
<AttributeMapping ClassAttribute="number">
      <Attribute>Number</Attribute>
    </AttributeMapping>
  </ClassElementMapping>


  <ClassElementMapping ElementTagName="Item" ClassName="JrcItem">
    <AttributeMapping ClassAttribute="number" >
      <Attribute>Number</Attribute>
    </AttributeMapping>
    <AttributeMapping ClassAttribute="description">
      <Attribute>Description</Attribute>
    </AttributeMapping>
    <AttributeMapping ClassAttribute="unitPrice">
      <Attribute>UnitPrice</Attribute>
    </AttributeMapping>
  </ClassElementMapping>

</XmlMappingSpec>'.


That will result in the following output from the AbtXmlMappingParser:

Code: Select all

'<Order number="O00001" status="Open">
   <Customer>
      <CustomerID name="Joe Akarski" number="C13579"></CustomerID>
      <Address>
         <Street>10 Main Street</Street>
         <City>Anytown</City>
         <State>AnyState</State>
         <PostalCode>12345</PostalCode>
         <Country>USA</Country>
      </Address>
      <Contact>Joe</Contact>
      <Phone>555-1212</Phone>
   </Customer>
   <LineItems>
      <LineItem number="1">
         <Quantity>12</Quantity>
         <Item number="I12345">
            <Description>Roses</Description>
            <UnitPrice>$3.50</UnitPrice>
         </Item>
      </LineItem>
      <LineItem number="2">
         <Quantity>1</Quantity>
         <Item number="I67890">
            <Description>Box of Candy</Description>
            <UnitPrice>$5.50</UnitPrice>
         </Item>
      </LineItem>
      <LineItem number="3">
         <Quantity>1</Quantity>
         <Item number="I4567">
            <Description>Valentine''s Day Card</Description>
            <UnitPrice>$2.99</UnitPrice>
         </Item>
      </LineItem>
   </LineItems>
</Order>'

I will be happy to email a zip file with the entire example including a workspace and the Smalltalk classes to anyone who wants it.

[jtuchel]

Diane,

thanks a lot for your help. In fact, my error was not using a DTD or Schema, but only a mapping spec.
My code was correct, so were the xmls for mapping, I just have to add a schema to the game.

The docs aren't perfectly clear but there is a little warning that if you don't use both mapping spec and DTD/XSD, the results may differ.

Again, thanks!

[tc]

Hello,

Yes, a schema file (.xsd) is used to create ST classes in your designated app:

Code: Select all

AbxXmlSchemaToClass new
   createClassesFrom: 'd:\temp\vast xml\invoice.xsd'
   in: MyAbtXmlSchemaClassesApp
   replace: true

The schema file is also used to generate a mapping file:

Code: Select all

AbxXmlSchemaToMappingFile new
   createMappingFileNamed: 'd:\temp\vast xml\invoice.map'
   from: 'd:\temp\vast xml\invoice.xsd'

Both the mapping spec and DOM tree are needed to create objects from the XML.

--tc